Water and fire tube boiler



Sept. 12, 1950 YM. E. MILLER 2,522,392

WATER AND FIRE TUBE BQILER.

Filed April 24, 1947 a Sheets-Sheet 1 5 a nick i- Uijfl- 23 m g g; df.

6' kg 0 0 50 0 5; kg 0 e o v 0 36- :93 v i 37 74 E U1E1-E1 I 1 INVJ ZNTOR, Michael E/MLZZen a5 ATTORNEY.

Sept. 12, 1950 M. E. MILLER WATER'AND FIRE TUBE BOILER a Sheefs-Shet 2 Filed April 24, 1947 l lll l.

INVENTOR,

MichaeZZ'ZA/IiZZm;

ATTOFINEV.

Sept. 12, 1950 M. E; MILLER WATER AND FIRE TUBE BOILER 8 Sheets-Sheet 5 Filed April 24, 1947 I INVENTOR, Michael E MIJZ Z673 ATTORNEY.

Sept. 12, 1950 M. E. MILLER WATER AND 'FIRE TUBE BOILER Filed April 24, 1947 8 Sheets-Sheet {1 Q @Q QQ U W? .m TZ nn w WM T [E A W w m w W Sept. 12, 1950 M. E. MILLER WATER AND FIRE TUBE BOILER.

Filed April 24, 1947 8 Sheet's-Sheet 5 twin-c,

2? INVENTOR, MiahaeZ E MzLZZer,

ATTORNEY.

p 12, 1950 2 v M. E. MILLER 2,522,392

WATER AND FIRE TUBE BOILER Filed April 24, 1947 8 Sheet s-Sheet 6 G a I I ,2 a o r \1 D 5' "QT ATTORNEY.

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Sept. 12, 1950 Filed April 24, 1947 Sept. 12, 1950 M. E. MILLER WATER AND FIRE TUBE BOILER Filed April 24, 1947 8 Sheets-Sheet 8 v Elma/r1400, Micfiael E ML'ZZen UNITED STATE s. P TENT OFFICE! WATER AND FIRE TUBE BOILER Michael E. Miller, Santa Barbara, Calif. Application April 24, 1947, Serial No. 743,604

15 was. (o1.122 22s) both combined water tube and fire tube sections and uptake SBCtlOIlSWlthOllt? tubes so' that the gases can be directed to a-sm'oke box at the front of the boiler and uptake sections with tubes so that the smoke box can be located at either the front or back of the boiler fora two or three pass boiler.

A further object is to provide a sectional sheet metal boiler that will be made up in anassembly of front and rear waterlegs or'headers towhich uptake and. water tube intermediate sectionsare joined so that all water tube heating surface is exposed in the fire box and the horizontal fire tubes form the gas passageways through the water spaces of the boiler andin which the cross sectional area of the fire tubes in thefirst pass bears the relation to the cross sectional area of the fire tubes in the last pass as baiiling. p y

, Another object is to providea boiler composed of sheet metal sections, some of which havefire tubes through their water spaces or other sections having water tubes exposed in the fire box and .antherconstituting the back wallof the firebox having horizontalfire tubes only for limiting the grate area.

Other, objects will be obvious.

H To the attainment ofthe aforesaid objects and ends invention resides in thenovel details of .construction, combination and arrangementof parts all of which will first be described in detail and then be specifically pointed out in the appended claims reference being had to the accompanying drawings in which: i

Fig. 1 is a front elevation illustrating my new and improving boiler as a three pass boiler.

Fig. 2 is a rear elevation of the same.

Fig. 3 is a side elevation of the same.

Fig. 4 is a front elevation of the front header.

Fig. 5 is a rear elevation of the rear header.

Fig. .6 is a front elevation, of the uptake section of athree pass boilers.

Fig. 7 is a front elevation of a combined water ube and fire tube section. v h Fig. 8 is a front elevation of. an intermediate all fire tube section. I

. .sary), fire tubes Ill, va-clean out opening sheet ll Again it is an object to provide a boiler having l 25 assembly for use with oil, gas or stoker.

2 "1 Fig. 9 is a front elevation of an intermediate fire tube waterleg fire box section. Fig. 10 is an enlarged detail section on theline |c |0 ofFig. 11. 2

I i 11 is a section on the line I l-Il of Fig 10. Fig. 12 is a section on the line I2-l 2*of Fig.4; Fig. 13 isa section on the line l3l3 of Fig.5. Fig. 14 is a view similar to Fig. 'l of a modification.

Fig. 15 is a view similar to Fig. 3 showing a two pass boiler.

Fig. 16 is a front elevation of sections of the boiler of Fig. 15.

Fig; 1'7 is a detail cross section .on-the line Il-ll of Fig; 18. .1 g z I Fig. 18 is a side'elevation showing a combination of sections constituting a sectional portable firebox type boiler'for use with. hand fired hard fuels.

Fig. 19 is a view similar to Fig. 18 schematically one ofthe uptake illustrating a boiler composed of front and back headers A and F, four sections B, three sections D and two sections E. I Fig. 20 is a view similar to Fig. 15 showing an i Fig. 21 is an enlarged detail cross section on the line 2l-2l of Fig. 10.

Referring now to the accompanying drawings in which likenumerals and letters of reference indicate like parts in all the figures, A indicates the front header, B the combined water tube and fire tube waterleg sections, C fire tube waterleg sections, D the intermediate fire box all fire'tube se'cticnsE the uptake sections, and F the rear header.. I 5 v i For purposes of illustration only Fig. 3 shows-a boiler having a front header A, ten combined water tube and fire tube waterleg sections B, four intermediate fire box fire tube sectionsD, two uptake sections E, and a backv header F, for a, three pass boiler, while Fig. 15 shows a two pass boiler having one front header, ten combined water tube and fire tube waterleg sections, two uptake sections and one back header. Any oombinations of the sections B, C, D and E can be used as may be desired.

' The front header The front headers are constructed of a front sheet I and a back sheet 2, a wrapper sheet 3, male and female fittings 4 and 6 respectively, hollow stay bolts 1, solid stay bolts 9 (if necesa firing opening sheet I2, a cast iron front ,plate :Ilgon which; is mounted a soot cleanbut door 3 frame l3 and doors [4, other clean out doors and a firing door I6.

Removable plugs 5 are used to close all exposed fittings that are not used for connection to the circulatin pipes (not shown) of the heating system.

The wrapper sheet 3 of the front header is set in from the edges of the front and back sheets I and 2 and these three sheets are welded together on the outside as at w.

The combined fire tube and water tube sections The fire and water tube sections B. each comprises a front plate '32, a back plate 33, a wrapper sheet 34, male nipples 35, female nipples 36, hollow stay bolts 3'], solid stay bolts 38, fire tubes 39, water tubes 40, reinforcing plates 4| and clean out plugs 42 for access to the water tubes.

In these sections the front and back sheets 32. 33. are. set in from the edges of the wrapper sheet 34 and welded thereto on the outside as at w Fig. 11.

The water tubes 40 may be arranged as shown in Fig. or as shown at 40* in Fig. 14 as may be desired. Preferably the arrangement shown in Fig, 10- is used as with this arrangement it is easier to clean out the water tubes when necessary.

The fire tubes 39 are welded to the sheets 32, 33 on the outside as at win Fig. 11.

The fire tube waterZeg sections As shown in Figs. 3 and 9 each fire tube waterleg section comprises a front sheet 43, a back sheet 44, a wrapper sheet 45, male and female nipples 46, hollow stay bolts 41, solid stay bolts 48 (if necessary) and fire tubes 49.

The front and back sheets are set in from the wrapper sheet and welded to the same on the outside. The fir'e tubes 49 are also welded on the outside to the front and back plates, or they may be expanded to the front and back plates.

Each intermediate section preferably has. that portion of the wrapper sheet which is exposed to the fire corrugated as at 74 (Figs l0, l1, and 21) to increase the surface area exposed to the heat of the furnace. Solid stay bolts may also be secured to the wrapper sheet at suitable locations.

The intermediate fire box fire tube section These sections as shown in Figs. 3 and 8 each comprises a front sheet 5!, a back sheet 52, a wrapper sheet 53, male and female nipples 54, hollow stay bolts 55, solid stay bolts 56 (if necessary) and fire tubes 57.

Thefront and back sheets are set in from the edges of the wrapper sheet and welded on the outside to the same. The fire tubes are also welded to the front and back sheets on the outside, or they may be expanded to the front and back sheets.

The uptake sections These sections, like the other sections located between the front and back headers, are each composed of a front sheet 58, a back sheet 59, a wrapper sheet 30, welded together on the outside, male and female nipples 6|, hollow stay bolts 62, solid stay bolts 63 and fire tubes 64. The front and back plates are set in from the edges of the wrapper sheet as in the aforementioned sections B, C and D, For a three pass boiler the uptake sections have only two rows of smoke tubes and 'may be made in one part, while the sections B, C

The back header This header, like the front header, is composed of a front sheet iii, a back sheet IS, a wrapper sheet 20, front male fittings 2|, back female fittings 22, plugs 23 for openings not used for piping connection, fire tubes 24, hollow stay bolts 25 and solid stay .bolts 26.

A smoke box 28 has its mounting plate 21 secured to the back wall l9 over the outlet ends of the fire tubes 24, the smoke box having a pipe collar 29, a cover 30 and a damper 3|.

As in the front header, so in the back header, the wrapper sheet is set in from the edges of the front and back sheets and welded thereto on the outside.

Figs. 17 and 18 illustrate a steam boiler, without water tubes, for use with a grate and coal fuel, liand firing. In these figures a slightly modified construction of the section D is shown in that there is one more row of fire tubes than is shown in section D in Fig. 8 for instance, This boiler may be used in place of the present portable fire box boilers that are made in one piece. In Figs. 1? and 18 I have shown a steam drum 6'! connected to every other intermediate section by pipes 68. The steam pipes to the radiators of the heatingsystem are indicated by 69-. T2 is a damper and Ill and H indicate ash and clean out doors while 13 indicates a crown sheet.

The arrangement shown in Fig. 19 is self-explanatory as is also that shown in Fig, 20 so a detailed description of the same here is thought to be unnecessary. The boiler when used with gas, oil or stoker would, in practice, be assembled without sections D. When sections C and D are assembled it will not be necessary to use the clean out plugs 42 or to use the reinforcing plate 4| as sections C or D do not have the water tubes.

In general The hollow male and female fittings of the several intermediate sections and the front and back headers line up as do the hollow stay bolts. When the several sections of the boiler are in position on the base 65 tie rods 8 are passed through the aligned hollow stay bolts and the sections drawn tightli together.

The nipples provide means for effecting com,- munication between the water spaces of adjacent sections of the boiler, and may be either tapered metal joints or made with packing rings, the metal to metal joint being preferred.

For low pressures only one tie rod is provided for each taper socket but for higher pressures more hollow stay bolts are used both being in line with the socket so as to bring them evenly to their seats and provide for strengthening the place adjacent to the sockets.

The grate bars of the boiler are indicated by the reference number 63.

The dimensions of the several parts of the boiler may be varied to suit the particular requirements of the builder or manufacturer.

The design is such that by increasing the length of the waterleg, the distance from the grate to the nearest heating surface of the exposed water tubes in the firebox can be made to meet the requirements of the stoker manufacturers or to secure the required volume to take care of practical overloads. It will be found that by increasing the length of the waterle to secure the recommended height above the grate the furnace volume will be greater than that established by practice for either stokers, gas, or oil. This is a decided advantage in a low E. t. u. release per cu. ft. and for completion of combustion within the firebox. The waterlegs may be shortened if the boiler is tobe fired with hard coal and grate bars can be set at proper height in the firebox by raising the grate bar suspension.

The boilers can be made in all regular sizes and ratings for either hand or mechanical firing. They exceed the requirements of-the Steel Boiler Institute, in grate area, square feet of heatingsurface and furnace volume. v

The water tubes induce circulation in the 'waterlegs of the sections and accelerate the fiow of water over the crown sheet and around the fire tubes and also provide for additional heating surface in the fire box exposed to radiant heat.

The boilers can be assembled with all intermediate sections with the 'water tube and uptake sections to form a two or three passboiler or the boiler can be assembled using a combination of intermediate water tube sections and fire tube sections and the uptake sections to form the passageway for the gases. The boiler can be assembled using fire tube sections to form the fire box of the boiler by omitting the water tubes and intermediate fire tube sections with the fire tubes below the crown sheet and uptake sections to make a portable type of sectional boiler,

By using uptake sections without tubes the gases can be directed to the smoke box at the front of the boiler and the smoke pipe can be taken off at the front of the boiler, so that the boilers can be made for either front or rear smoke pipe connections.

In Figs. 15 and 16, those parts which are identical with like parts in Fig. 3 bear the same ref-'- erence letters and numerals while those parts which are modified bear the index letter I). The uptake sections E are of like construction to the uptake sections E except that the fire tubes of sections E are omitted from sections E (compare Figs. 6 and 16).

' In order to simplify the assembling of'sections it may be advisable to make the taper sockets half male-on the right or left hand side of the front header and female on the otherhalf. On the rear header the taper sockets would be the reverse 7 hand from what they are on thefront header.

This will make it possible to make a replacement of any section in case of arepair by havingon hand a half section of any of the different types of sections used and thus not lay-uptheboiler.

fThe damaged section can be later repaired and held as a spare.

The boiler can be made by pressing or forming one end and the two sides and welding the outside endplate to the pressed section or by seaming the end plate tothe pressed section. The

sockets between the sections need not be male and female tapered joints on low pressure work as a packed joint could be used for this purpose since it is not necessary that the sides of the sections fit metal to metal.

nection with the accompanying drawings it" is thought the construction and advantages of my improved boiler will be clear to those skilled in the art.

What I claim is:

l. A sheet metal water tube boiler which includes:' a front waterleg; a back waterleg; and intermediate sections, said sections and said waterlegs each including a front sheet and a back sheet and a wrapper sheet, the front and back waterlegs havin cleanout passages, the front waterleg having a firing door and a clinker door; the intermediate sections each including a horizontal water and steam space and at least one vertical waterleg and water tubes connecting the horizontal space with the vertical waterleg; hollow stay bolts in each intermediate section and in the front and back waterlegs., the stay bolts of the several sections and waterlegs lining up with one another; and tie rods passed through the hollow stay bolts and clamping the sections together; the intermediate sections and the front and back waterlegs havin communicating passages; and cleanout plugs opposite the ends of said water tubes.

2. In a sheet metal water tube boiler having front and back waterlegs and intermediate sections, enclosing a firing chamber, the improvement which comprises: intermediate sections each including an inverted L-shaped-infrontelevation body composed in part of a front wall, a back wall and a wrapper sheet, the front and back walls being set in from the edges of the wrapper sheet and weldedtogether on the outside of the sections.

3. In a sheet metal water tube boiler having front and back waterlegs and intermediate sections, enclosing a firing chamber, the improvement which comprises: intermediate sections each including an inverted L.-shapedin-frontelevation body composed in part of a front wall, a back'wall and a wrapper sheet, the front and back walls being set in from the edges of the wrapper sheet and welded together on the outside of the sections, and water tubes having their respective ends secured to and in communication with two legs of the L and lying in the angle of the same; and cleanout doors located in the outer part of the wrapper sheet and opposite the respective ends of said water tubes.

4. A sheet metal water tub-e boiler having a front waterleg; a back waterleg; intermediate water-leg sections; male'and female sockets carried by said waterlegs and said intermediate sections for effecting communication between the same, said intermediate sections each including a top horizontal chamber and a vertical side chamber, and water tubes each having one end secured to and communicating with the top chamber and the other end secured to and .communicating with the vertical side chamber and lying in the angle between said top and side chambers, there being a firing chamber below said tubes; and horizontal front-to-back Water tubes communicating with and secured to the front and back waterlegs.

said tubes; and horizontal front-to-back water tubes, communicating with and secured to the front and back waterlegs, said front-to-back water tubes lying adjacent said intermediate sections water tubes at the upper part of the firing chamber.

6. In a sheet metal Water tube boiler having a front waterleg, a back waterleg and intermediate waterleg sections, and a firing chamber, the improvement which includes: intermediate sections each of inverted L-shape-in-front-elevation, said intermediate sections each including a front wall, a back wall, and a wrapper sheet, that portion of the wrapper sheet adjacent the firing chamber being corrugated; and water tubes having vertical portions the ends of which are secured to the top part of the inverted L and having horizontal portions the ends of which are secured to the vertical part of the L, said tubes being in communication with the interiors of both legs of the L.

7. A sectional water tube boiler the sections of which are constructed of sheet steel walls enclosing vertical and top horizontal water spaces; the boiler including a combustion chamber having smoke outlets; water tubes in the combustion chamber, some of said tubes having one end of each tube connected so as to communicate with the horizontal water space of a section and the other end of the same tube being connected so as to communicate with the vertical water space of the same section; male and female socket connections between the several sections; means for securing the several sections to.- gether; firing, clinker and cleanout doors for the front section; the rear section having smoke outlets; and a smoke box connected with said rear section outlets, said smoke box itself having at least one smoke outlet.

8. A sectional water tube boiler the sections of which are constructed of sheet steel Walls enclosing vertical and top horizontal water spaces; the boiler including a combustion chamber having smoke outlets; Water tubes in the combustion chamber, some of said tubes having one end of each tube connected so as to communicate with the horizontal water space of a section and the other end of the same tube being connected so as to communicate with the vertical water space of the same section; male and female socket connections between the several sections; means for securing the several sections together; firing, clinker and cleanout doors for the front section; the rear section having smoke outlets; a smoke box connected with said rear section outlets, said smoke box itself having at least one smoke outlet; and horizontal water tubes connecting the front. and back sections and passing through the combustion chamber.

9. In a sheet metal boiler having front and back waterlegs and at least one intermediate section enclosing a firing chamber, the improvement which comprises an intermediate section that includes a body composed in part of a front wall, a back wall and a wrapper sheet, the front and back walls being set in from the edges of the wrapper sheet and welded together on the outside of the section.

10. In a sheet metal boiler having front and back waterlegs and at least one intermediate section enclosing a firing chamber, the improvement which comprises an intermediate section that includes a body composed in part of a front wall, a back wall and a wrapper sheet, the front and back walls being set in from the edges of 8: the wrapper sheet and welded together on the outside of the section, that part of the wrapper sheet which is adjacent the firing chamber be? ing corrugated.

11. In a. sheet metal boiler having frontv and back waterlegs and at least one intermediate section enclosing a firing chamber, the improvement which comprises an intermediate section that includes a body composed in part of a front, Wall, a back wall and a wrapper sheet, the front and back walls being set in from the edges of the wrapper sheet and welded together on the'outside of the section, that part of the wrapper sheet which is adjacent the firing chamber being corrugated and tied to the opposite wall of the wrapper sheet bytie bolts.

12. In a sheet metal water tube boiler having frontand back waterlegs and intermediate sections, enclosing a firing chamber, the improvement which comprises: intermediate sections each including an inverted L-shaped-in-fmntel vat cn. bed-v compo i pa of a front, Wall, a back wall and a wrapper sheet, the front and back walls being set in from the edges of the wrapper sheet and welded together on the outr front waterleg; a back waterleg; intermediate \vaterleg sections; male and female sockets carried by said waterlegs and said intermediate sections for effecting communication between the same, said intermediate sections each including a top horizontal chamber and a vertical side chamber, and water tubes each having one end secured to and communicating with the top chamber and the other end secured to and communicating with the vertical side chamber and lying in the angle between said top and side chambers; fire tubes in the top chamber, the ends of the fire tubes being respectively connected to the front and back walls of the waterleg sections, there being a, firing chamber below said tubes; and horizontal front-to-back water tubes cominunicating with and secured to the front and back waterlegs.

14. A furnace having a front water leg, a back water leg, and intermediate water legs, male and female connections between the respective water legs for circulation of the Water in the furnace, said intermediate water legs constituting the sides and top of a fire box, bent water tubes lo,- cated, in the fire box for each intermediate water lee, said bent, water tubes having one end of each secured to the side of its water leg and having the other end of each secured to the top of its water leg, fire tubes for each intermediate water leg, said fire tubes extending horizontally and being mounted in the respective intermediate water legs above the fire box, the fire tubes of one water leg abutting those of an adjacent water leg to constitute passages for products of combustion from the fire box to a. smoke outlet for the furnace, the fire tubes being immersed in water when the furnace is in use, and means foroperatively securing the several water legs together.

15. A furnace having a smoke outlet and having a fire box which is provided with side walls, a back wall, and a crown sheet, surroundcd, by a fire tubes, and means for effecting operative connection between the other end of said fire tubes and the smoke outlet of the furnace.

MICHAEL E. MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 486,467 Higgins Nov. 22, 1892 688,324 McMullan Dec. 10, 1901 965,758 Seizer July 26, 1910 1,111,267 McClellan Sept. 22, 1914 1,355,049 Kent Oct. 5, 1920 1,767,235 Birchfield June 24, 1930 2,070,559 Berent Feb. 16, 1937 

